碳纳米管传感器

Polyaniline/multiwall carbon nanotube nanocomposite for detecting aromatic hydrocarbon vapors

Wei Li •Dojin Kim

Received:5September 2010/Accepted:15October 2010/Published online:26October 2010ÓSpringer Science+Business Media,LLC 2010

Abstract In this paper,polyaniline/multiwall carbon nanotube (PANI/MWCNT)composites were fabricated through an in situ polymerization method and were applied for the detection of aromatic hydrocarbon vapors.The composites were characterized by scanning electron microscopy (SEM),Fourier transform infrared spectros-copy,and Raman spectroscopy.The SEM results showed that the PANI was uniformly coated on the MWCNT,and the coating thickness was dependent on the mass ratio of aniline monomer to MWCNT.The response to aromatic hydrocarbon vapors was investigated in several hundreds ppm ranges.The sensor showed an increase in conductiv-ity,and the maximum response measured at 1000ppm was several tens of percent.

Introduction

Aromatic hydrocarbons are important solvents and pre-cursors used in synthetic chemistry.They are also well recognized as serious hazards both to the environment and to human health.For example,according to the World Health Organization (WHO),benzene has an adverse effect on human blood,immunity,reproduction,genes,and so on [1].Hence,appropriate sensors are required in working environments to warn of aromatic hydrocarbon exposures before they jeopardize the safety of workers.However,so far,the comprehensive studies on chemiresistive sensors able to detect aromatic hydrocarbon vapors are very few in

comparison with those on inorganic gases,such as NH 3,H 2,CO,and NO.

Presently,the preparation of nanocomposites involving the combination of carbon nanotube (CNT)and conducting polymers has received considerable attention.The combi-nation of CNT and conducting polymers is expected to merge and enhance the unique properties of each compo-nent and to conquer effectively the limitation of the poor interaction between the pristine nanotube and gas molecule [2,3].Of the family of conducting polymers,polyaniline (PANI)is perhaps the most intensively studied due to its high environmental stability,stable electrical conduction,and unique acid/base doping/dedoping chemistry.A num-ber of studies on PANI/CNT composite gas sensors have been reported in the past several years [3–7].To the best of our knowledge,however,no comprehensive reports on a PANI/CNT composite being used as sensor for aromatic hydrocarbon vapors has been published.As these organic vapors are fatal to both humans and the environment,there is a need to develop a reliable sensor to detect them.Therefore,a study on polyaniline/multiwall carbon nano-tube (PANI/MWCNT)composites for the detection of aromatic hydrocarbon vapors was carried out and presented in this paper.

Experimental procedure Materials

Highly purified MWCNTs ([95%)with diameter of 60–90nm were purchased from NanoKarbon Co.Ltd.,Korea.All chemicals and solvents of the highest com-mercially available purity were purchased from Sigma–Aldrich and were used without further purification.

W.Li ÁD.Kim (&)

Department of Material Science and Engineering,Chungnam National University,Daejeon,Korea e-mail:dojin@cnu.ac.kr

J Mater Sci (2011)46:1857–1861DOI 10.1007/s10853-010-5013-3